I have an issue with deleting specific text from a hidden Data Label I use to combine workflow actions for email notifications. For example, I have a hidden Data Label (hdnViewNotifications) for each view on my form that combines all of the notifications that might be triggered on that View any time the form is filled out. To add a notification's name to the hdnViewNotifications control I use the Transfer Data and add the hdnViewNotification control and that specific notification's name with a comma after the activity, so that the hdnViewNotification combines all of the View's notifications in that single control (see attachment). Then when the form is saved a rule pulls each View's hdnViewNotification control to add all of the appropriate notifications to the workflow.
Sometimes users change a control so it adds the notification's name to the hdnViewNotifications and then reset the control. If a control that triggers a notification is reset, I would like to remove that specific notification's name from the hdnViewNotifications. Can anyone direct me on how to "clear" a specific notification name from the hdnViewNotifications control without clearing any other notification names that might have also been added to the control? Do I have to repopulate the hidden control with an expression created to remove the specific notification's name? If so, any pointers on how to build the expression would be greatly appreciated as I'm not very comfortable with expressions.